DE102016100209A1 - HYBRID VEHICLE AND METHOD FOR RELEASING AN OVERDRIVE COUPLING IN A HYBRID VEHICLE - Google Patents

Abstract

A vehicle includes an engine and an electric machine connected to a planetary gear, a one-way clutch and a controller. The overrunning clutch transmits torque from the planetary gear to an overdrive wheel. The controller increases torque of the electric machine based on a torque command for the electric machine and the torque transmitted from the planetary gear to the overdrive wheel in response to a condition requiring disengagement of the one-way clutch.

Description

TECHNICAL AREA

The present disclosure relates to powertrains for hybrid electric vehicles.

BACKGROUND

One class of hybrid electric vehicle powertrains, commonly referred to as a power split powertrain, includes two energy sources. The first source includes an internal combustion engine and the second source includes a combination of an electric motor, a generator, and a battery. The engine and generator, along with a planetary gear set, countershaft, and motor, provide a mechanical torque flow path and an electromechanical torque flow path to vehicle drive wheels. The battery is an energy storage device for the generator and the engine. Engine power is split into two power flow paths at any generator speed and vehicle speed. The engine speed is controlled by the generator, which means that the engine speed within the allowable speed range of the generator may be decoupled from the vehicle speed. This mode of operation, in which the generator generates electrical power using mechanical power input from the engine, is referred to as a "positive power split."

Due to the mechanical properties of the planetary gear set, the generator can output power to the planetary gear set for driving the vehicle. This mode of operation is referred to as "negative power split". The combination of a generator, an engine, and a planetary gear set may thus be considered to have the characteristics of an electric continuously variable transmission (e-CVT).

A generator brake may be activated so that the engine output power is transmitted at a fixed gear ratio only via a mechanical path to the torque output side of the powertrain. The first power source can only affect forward propulsion of the vehicle because there is no reverse gear. The engine requires either generator control or application of a generator brake to transmit forward power output.

When the second power source is active, the electric motor draws power from the battery and drives the vehicle for both forward and reverse regardless of the engine. The engine may also generate power and charge the battery when the engine generates power that exceeds the driver demand or in a recuperation mode in which vehicle kinetic energy is consumed. In addition, the generator may draw power from the battery and propel against an overrunning clutch on the output shaft of the engine to propel the vehicle in a forward direction. This mode of operation is referred to as "generator drive mode". A vehicle system controller coordinates the two sources of energy so that they work together seamlessly to meet a driver torque request without exceeding powertrain system limits. The vehicle system control allows continuous control of engine speed for any given vehicle speed and power demand. The mechanical power flow path provides efficient power output through the planetary gearset to the drive shaft.

SHORT VERSION

In one example, a vehicle includes an engine and an electric machine connected to a planetary gear, a one-way clutch configured to transmit torque from the planetary gear to an overdrive wheel, and a controller. The controller increases torque of the electric machine based on the torque transmitted from the planetary gear to the overdrive wheel in response to a condition requiring disengagement of the one-way clutch.

In another example, a hybrid vehicle includes a planetary gear set, an engine, an overdrive transmission, a one-way clutch, a generator, and a controller. The planetary gear set has a sun gear, a carrier wheel and a ring gear. The ring gear is configured to transmit torque to a drive wheel. The engine is connected to the carrier wheel and is configured to transmit torque to the planetary gear set. The overdrive wheel is configured to transmit torque from the engine to the drive wheel. The overrunning clutch is configured to shift between driveline and overdrive modes of operation to transmit torque from the planetary gear set to the overdrive wheel. The generator is connected to the sun gear and is configured to allow the overrunning clutch to coast when it is rotated in a disengaging direction. In response to a condition requiring switching from the powertrain overdrive mode to the powertrain rated operating mode, the controller changes a torque of the generator in the disengaging direction according to a torque command based on the torque transmitted from the planetary gear set to the overdrive wheel ,

In yet another example, a method for controlling a vehicle is disclosed. The vehicle includes an engine and an electric machine connected to a planetary gear set, and an overrunning clutch configured to transmit torque from the planetary gear set to an overdrive wheel. In response to a condition requiring disengagement of the one-way clutch, a torque of the electric machine is increased based on the torque transmitted from the planetary gear set to the overdrive wheel.

BRIEF DESCRIPTION OF THE DRAWINGS

1 illustrates a hybrid vehicle with a power split powertrain;

2 represents torque and speed transmission through a power split powertrain;

3 FIG. 12 illustrates a hybrid vehicle having a powertrain in accordance with the present disclosure; FIG.

4 and 9 illustrate flowchart control algorithms according to the present disclosure;

5 is a schematic view of an electromagnetic overrunning clutch;

6 is a detailed view of an electromagnetic overrunning clutch;

7A and 7B illustrate methods of engaging an overrunning clutch or claw clutch in accordance with the present disclosure in flowchart form;

8A and 8B FIG. 4 illustrates a flow chart disengagement method of a one-way clutch according to the present disclosure; FIG.

10 depicts an algorithm for controlling the generator when operating in nominal operating mode in flow chart form;

11A Fig. 10 illustrates in flowchart form an algorithm for controlling the generator, including a nominal mode of operation and an overdrive mode of operation; and

11B illustrates the total torque output of the hybrid vehicle powertrain in flowchart form.

DETAILED DESCRIPTION

Embodiments of the present disclosure will be described herein. It should be understood, however, that the disclosed embodiments are merely examples and other embodiments may take various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. The specific structural and functional details disclosed herein are therefore not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art how to variously employ the present invention. As would be apparent to one of ordinary skill in the art, various features illustrated and described with reference to one of the figures may be combined with other features illustrated in one or more other figures to provide embodiments that are not explicitly illustrated or described. The combinations of illustrated features provide embodiments for typical applications. However, various combinations and modifications of features consistent with the teachings of the present disclosure may be desired for particular applications or implementations.

Now on 1 Referring to FIG. 1, a hybrid electric vehicle is shown with a power split powertrain. The powertrain includes two power sources connected to the driveline: (1) an engine 16 and an electric machine 50 (which may be referred to as a generator) via a planetary gear arrangement 20 connected to each other; and (2) an electric drive system that includes a battery 12 , an electric machine 46 (which can be referred to as a motor) and a generator 50 contains. The battery 12 is an energy storage system for the engine 46 and the generator 50 ,

A vehicle system controller (VSC) 10 is configured to provide control signals to the battery 12 and / or the engine 16 and / or the engine 46 and / or the generator 50 to send and receive sensory feedback information from them, so that the vehicle drive wheels 40 Power can be supplied to drive the vehicle. The control 10 controls the energy source with proportioning between the battery 12 and the engine 16 to provide power to drive the vehicle, thereby controlling the state of charge (SOC) of the battery 12 ,

The gear 14 contains the planetary arrangement 20 that is a ring gear 22 , a sun wheel 24 and a carrier assembly 26 contains. The ring gear 22 gives torque to step wheels, the meshing gear elements 28 . 30 . 32 . 34 and 36 include. A torque output shaft 38 of the transmission 14 is through a differential and axle mechanism 42 with the wheels 40 drive-connected. The gears 30 . 32 and 34 are on a countershaft 31 attached, the gear 32 a motor driven gear 44 engages. The motor 46 drives the gear 44 at. The gear 44 acts as a torque input for the countershaft 31 , The engine 16 gives torque through the input shaft 18 to the gearbox 14 from. The battery 12 delivers to the engine 46 electrical power through the power flow path 48 , The generator 50 is with the battery 12 and the engine 46 electrically connected, as in 52 shown.

While the battery 12 when the engine is switched off 16 acts as the only source of energy, the input shaft 18 and the carrier assembly 26 by an overrunning clutch (OWC - one-way clutch) 53 braked. A mechanical brake 55 anchors the rotor of the generator 50 and the sun wheel 24 when the engine 16 is turned on and the drive train is in a parallel drive mode, wherein the sun gear 24 acts as a reaction element.

The control 10 receives a signal PRND (Parking, Reverse, Neutral, Driving) from a speed selector 63 , which together with a Sollraddrehmoment, a desired engine speed and a generator brake command, as in 71 shown to a transmission control module (TCM) 67 is transmitted. A battery switch 73 will be closed after a vehicle "key-in" start. The control 10 gives a desired engine torque request to the engine 16 out, like at 69 shown by the output of the accelerator pedal position sensor (APPS - accelerator pedal position sensor) 65 is dependent. A brake pedal position sensor (BPPS) provides a wheel brake signal to the controller 10 out, like at 61 shown. A braking system control module (not shown) may provide a regenerative braking command based on information from the BPPS to the controller 10 output. The TCM 67 gives a generator brake control signal to the generator brake 55 out. The TCM 67 continues to supply a generator control signal to the generator 50 out.

Now on 2 Referring to FIG. 12, a block diagram of the power flow paths between the various components of the powertrain of FIG 1 shown. Fuel is directed to the engine under the control of the driver using an engine throttle 16 delivered. The engine 16 provides engine power (τ _eng ω _eng , where τ _{eng is} the engine torque and ω _{eng is} the engine speed) to the planetary assembly 20 , The planet arrangement 20 provides power (τ _ring ω _ring , where τ _{ring is} the _ring gear torque and ω _{ring is} the _ring gear speed) to the countershaft 31 , The output shaft 38 gives power (P _out = τ _out ω _out , where τ _out and ω _out the torque or the speed of the output shaft 38 are) to the wheels 40 from. The generator 50 can the planetary arrangement 20 Deliver power or be powered by it. Likewise, the power distribution between the engine 46 and the countershaft 31 done in both directions. Drive power from the battery 12 or charging power for the battery 12 is through the bidirectional arrow 48 shown.

The engine output power (τ _eng ω _eng ) may be in a mechanical power flow _path (τ _ring ω _ring ) and an electrical power flow _path (τ _gen ω _gen to τ _mot ω _mot , where τ _{gen is} the generator torque, ω _{gen is} the generator speed, τ _mot that _Motor torque is, and ω _{mot is} the engine speed). In this so-called positive distribution mode of operation, the engine delivers 16 the planetary arrangement 20 Performance, the countershaft 31 Power (τ _ring ω _ring ) supplies, in turn, the wheels 40 rotates. Part of the planetary gear power (τ _gen ω _gen ) is sent to the generator 50 delivered, the charging energy to the battery 12 supplies. The battery 12 drives the engine 46 on, the power (τ _mot ω _mot ) to the countershaft 31 emits.

When the generator brake 55 is activated, a parallel operation mode is established. In the parallel mode configuration, the prime mover is 16 switched on and the generator 50 is slowed down. The battery 12 feeds the engine 46 who is the countershaft 31 simultaneously with the delivery of power from the engine 16 to the planetary arrangement 20 to the countershaft 31 drives. When operating with the second power source (as the battery 12 , the engine 46 and the generator 50 containing described), the engine pulls 46 Power from the battery 12 and provides drive independent of the engine 16 ready for the drive train.

As described, the HEV has two power sources to provide drive power to the wheels 40 , The first energy source contains the engine 16 and the second power source contains the battery 12 , The engine 16 and the battery 12 can provide drive power either simultaneously or independently. The control 10 controls the metering of electrical energy and fuel energy to meet the drive requirements, thereby controlling the engine 16 and the battery 12 corresponding.

As can be observed, the planetary gear arrangement gives 20 Speed and torque ratios between the engine 18 , the generator 50 and the vehicle drive wheels 40 in front. As discussed above, the generator can 50 be controlled to power from the engine 18 using the planetary gear arrangement 20 as a CVT to the vehicle drive wheels 40 transferred to. Under some operating conditions, those exceed by operation of the generator 50 However, losses caused the energy advantage of the CVT

For example, when the vehicle is in "steady state" operation, such as driving at a generally constant speed, the generator experiences 50 Operating losses that can exceed one kW while the gear ratio between the engine 16 and the drive wheels 40 generally unchanged. Here, stationary operation refers to a constant vehicle speed, a constant power demand by the driver, and a generally constant amount of engine power used to charge the vehicle. This generally occurs when the driver's power demand is approximately equal to the "running resistance" or the sum of vehicle-acting forces (eg, rolling resistance, aerodynamic drag, etc.).

Now on 3 With reference to the drawings, a powertrain according to the present disclosure is illustrated. The powertrain contains two energy sources that are connected to the transmission 14 ' and the driveline are: (1) an engine 16 ' and a generator 50 ' that have a planetary gear arrangement 20 ' connected to each other; and (2) an electric drive system that includes a battery 12 ' , an electric motor 46 ' and a generator 50 ' contains. The planetary gear arrangement 20 ' can be a ring gear 22 ' , a sun wheel 24 ' and a carrier assembly 26 ' contain. The engine 16 ' can with the carrier assembly 26 ' be coupled, and the generator 50 ' can with the sun gear 24 ' be coupled. The planetary gear arrangement 20 ' defined in conjunction with meshing gear elements 28 ' . 30 ' . 32 ' . 34 ' and 36 ' a first mechanical linkage between the engine 16 ' , the generator 50 ' and the drive wheels 40 ' , A mechanical linkage is made by meshing gear elements 44 ' and 32 ' , the output shaft 79 and meshing gear elements 34 ' and 36 ' between the engine 46 ' and the drive wheels 40 ' Are defined. The meshing gear elements 30 ' . 32 ' and 34 ' rotate around a common output shaft 79 , and the meshing gear elements 34 ' and 36 ' define an axle ratio between the output shaft 79 and the output shaft 38 ' , The output shaft 38 ' of the transmission 14 ' is through a differential and axle mechanism 42 ' with the wheels 40 ' drive-connected.

In addition, the powertrain includes a parallel overdrive shaft 80 firmly with the gear element 30 ' for a common rotation with the output shaft 79 is coupled. The overdrive wave 80 is with the gear element 82 coupled with the gear element 84 is in rotation. An overdrive clutch 86 is operable to the gear member 84 with the engine 16 ' selectively couple and torque from the planetary gear arrangement 20 ' transfer to an overdrive transmission assembly. The overdrive clutch 86 includes an engagement mechanism for transmitting torque from the planetary gear assembly 20 ' away and onto an overdrive gearbox. Examples of the engagement mechanism include, but are not limited to jaw clutches and overrunning clutches, such as an electronically controlled toggle clutch overrunning clutch. The meshing gear elements 84 and 82 have a fixed gear ratio configured to provide an overdrive speed and torque ratio between the engine 16 ' and the output shaft 79 to define if the overdrive clutch 86 is indented. A controller 88 is configured to overdrive the clutch 86 selectively responsive to engagement or disengagement in response to various operating conditions as described below with reference to FIG 4 will be discussed. Of course, there may be other transmission arrangements that have an overdrive speed ratio between the engine 16 ' and the output shaft 79 pretend to be used.

Now on 4 Referring to FIG. 1, a method for controlling the operation of the powertrain in flowchart form is illustrated. The hybrid vehicle powertrain is operated according to a nominal logic (or nominal mode) with the clutch disengaged, as in block 90 shown. A determination is then made as to whether a first operating condition is met, as in operation 92 shown. The first operating condition generally corresponds to a change from non-steady-state operation to steady-state operation or a decrease in the amount of difference between a driver's demand for power and the running resistance. The first operating condition may be one of the operating conditions of list A, which at block 94 is shown. The first operating condition may be a generally constant power demand by the driver through a first steady acceleration event. The first operating condition may also be a second acceleration event followed by a reduction of the power demand to be generally equal to the running resistance. The first acceleration event may also be a third acceleration event followed by a reduction in driver power demand and activation of recuperation braking. It should be noted that with respect to the acceleration events, "first", "second" and "third" are used for illustration and do not indicate any order or collapse. If the first operating condition is not met, control returns to block 90 back. When the first operating condition is met, the clutch is engaged and the driveline is controlled in overdrive mode, as in block 96 shown.

Then, a determination is made as to whether a second operating condition is satisfied, as in operation 98 shown. The second operating condition generally corresponds to another steady-state operation or a generally constant difference between the driver demanded power and the running resistance. The second operating condition may be one of the operating conditions of list B that is at block 100 is shown. The second operating condition may include a slight deviation of the vehicle speed or power demand by the driver. In some embodiments, a speed deviation threshold or power demand deviation threshold may be provided. In such embodiments, variations in speed or power demand that do not exceed the respective thresholds may satisfy the second operating condition. The second operating condition may also be a generally constant power demand by the driver with a change in the vehicle charging mode. In some speed and torque ranges, charging by using one motor is more efficient, and in other areas, charging by using a generator is more efficient. A change from engine charge to generator charge or from generator charge to engine load in conjunction with a generally constant power demand by the driver would thus meet the second operating condition. Similarly, a change from a "no-load" mode to a load mode in conjunction with a generally constant power demand by the driver would thus meet the second operating condition. If a determination is made that the second operating condition is met, then the clutch is held in the engaged position, as in block 102 shown. Then the controller returns to operation 98 back. Thus, the drive train is controlled in further stationary operation in overdrive mode.

If a determination is made that the second operating condition is not met, then a determination is made as to whether a third operating condition is met, as in block 104 shown. The third operating condition generally corresponds to a change from steady-state operation to non-stationary operation or an increase in the amount of difference between the driver's demand for power and the running resistance. The third operating condition may be one of the operating conditions of list C that is at block 106 is pictured. The third operating condition may be a large reduction in power demand or a large increase in power demand. In some embodiments, a power request deviation threshold is provided, and the third operating condition is satisfied when a deviation of the power demand by the driver exceeds the threshold. This may include a first threshold for power request decreases and a second threshold for power request increases. The third operating condition may also be a strong operation of vehicle brakes. In some embodiments, a brake threshold is provided, and the third operating condition is satisfied when a driver's brake application exceeds the threshold. The third operating condition may also be a large reduction in vehicle speed. For some Embodiments, a speed deviation threshold is provided, and the third condition is satisfied when a reduction in the vehicle speed exceeds the threshold. The third operating condition may be an engine shutdown request. When a battery state of charge is sufficient to assist the electric operation and an engine shutdown request is issued, the third condition is satisfied. If a determination is made that the third operating condition is not met, control goes to block 102 above. If the third operating condition is met, the clutch is disengaged, as in block 108 shown. Then the controller returns to block 90 back.

Although presented as a single controller, the controller can 88 may also be part of a larger control system and may be controlled by various other distributed throughout the vehicle controls such. For example, a vehicle system controller (VSC - Vehicle System Controller) can be controlled. It is therefore understood that the controller 88 and one or more other controllers may be collectively referred to as a "controller" that controls various actuators in response to signals from various sensors for controlling various functions. The control 88 may include a microprocessor or central processing unit (CPU) associated with various types of computer readable storage devices or media. Computer readable storage devices or media may include volatile and nonvolatile storage in, for example, read only memory (ROM), random access memory (RAM), and keep alive memory (KAM). The KAM is a persistent or non-volatile memory that can be used to store various operating variables while the CPU is off. The computer readable storage devices or media may be implemented using any of a number of known memory devices, such as PROMs (Programmable Read Only Memory), EPROMs (Electric PROMs), EEPROMs (Electrically Erasable PROMs), Flash Memory, or any other electrical, magnetic , optical or combination memory devices capable of storing data, some of which represent executable instructions used by the controller in controlling the engine or the vehicle.

Now on the 5 and 6 Referring to Fig. 11, a rocker-type overrunning clutch becomes 110 (which may be an electromagnetic clutch), as may be used in connection with the present disclosure, is shown schematically. In particular, the rocker overrunning clutch may be considered the overdrive clutch 86 used for selectively coupling the gear member 84 with the engine 16 ' can be used. The overrunning clutch 110 contains a rocker plate 112 with bags 114 , each bag 114 a corresponding rocker arm 116 contains in the respective pockets 114 is pivotally mounted. The coupling 110 also includes a cam plate 118 , the notches defining several teeth 120 having. When the rocker arms 16 concerning the bags 114 The teeth can be pivoted inwardly of parts of the rocker arms 116 take. The rocker arms 116 be from a spring 121 so preloaded that they stay in the pockets without protruding. In this configuration, there is no engagement between the rocker arms 16 and the notches 120 , and thus will between the rocker plate 112 and the cam disk 118 no torque transmitted. 5 puts the clutch 110 in this disengaged position.

The cam disk 118 includes a coil (not shown) that can be selectively energized to generate a magnetic force and the clutch 110 to engage. In response to the magnetic force, the rocker arms pivot 116 against the preload of the spring 121 out of the pockets 114 to the outside, leaving part of the rocker arm 116 via a radially inner surface of the rocker plate 112 protrudes. The protruding part of the rocker arms 116 can in the notches 120 engage and torque between the rocker plate 112 and the cam disk 118 transmitted in one direction of rotation. 6 puts the clutch 110 in this engaged position.

Referring now to the 7A and 7B For example, methods of engaging a clutch as may be used in connection with the present disclosure are illustrated. 7A illustrates a method of engaging an overrunning clutch. The generator is controlled to allow the clutch to coast, as in block 122 shown. This can be done by turning the rocker plate in a disengaging direction. Then the clutch is activated, as in block 124 shown. As above with reference to 6 This may include energizing a coil to generate a magnetic field, whereupon the rocker arms pivot and engage the notches in a cam disk. Then the clutch is engaged as in block 126 shown. This is done by rotating the rocker disk a short distance in an engagement direction to engage the rocker arms with teeth in the cam disk. Torque carried by the generator is then transferred to the clutch as in block 128 shown.

7B illustrates a method of engaging a dog clutch. A generator speed is controlled to a target speed for synchronization with the clutch, as in block 130 shown. The clutch is then engaged, as in block 132 shown. Torque carried by the generator is then transferred to the clutch as in block 134 shown.

Now on the 8A and 8B Referring to Figure 1, methods for disengaging a clutch as may be used in connection with the present disclosure are illustrated. 8A illustrates a method of disengaging a one-way clutch. Torque carried by the clutch is transmitted to the generator as in block 136 shown. The generator is controlled to let the clutch free, as in block 138 shown. This can be done by turning the generator in the disengaging direction. Then the clutch is deactivated, as in block 140 shown. Then the generator control is returned to nominal operation, as in block 142 shown.

8B illustrates a method of disengaging a dog clutch. Torque carried by the clutch is transmitted to the generator as in block 144 shown. Then the clutch is disengaged, as in block 146 shown. Then the generator control is returned to nominal operation, as in block 148 shown.

wobei τ_gen das Drehmoment des Generators 50' ist, τ_eng das Drehmoment der Kraftmaschine 16' ist und ρ ein Verhältnis (N_s/N_r) der Anzahl von Zähnen (N_s) im Sonnenrad 24' zu der Anzahl von Zähnen (N_r) im Hohlrad 22' ist. In einem Beispiel weist das Sonnenrad 24' 34 Zähne auf (N_s = 34) und weist das Hohlrad 22' 86 Zähne auf (N_r = 86), was ein Verhältnis ρ von 0,395 ergibt.In accordance with various aspects of the present disclosure, a method and system for controlling the powertrain based on an estimated torque level transmitted by the clutch upon engagement of the overdrive clutch by the clutch is provided for smooth transition into and out of overdrive mode. For this purpose, a generator reaction ratio (GRR) may be determined and implemented in the normal powertrain torque calculations. The GRR is a ratio of generator torque to engine torque with the gears in the planetary gear assembly 20 ' to be considered:

where τ _{gen is} the torque of the generator 50 ' is, τ _eng the torque of the engine 16 ' and ρ is a ratio (N _s / N _r ) of the number of teeth (N _s ) in the sun gear 24 ' to the number of teeth (N _r ) in the ring gear 22 ' is. In one example, the sun gear points 24 ' 34 teeth on (N _s = 34) and has the ring gear 22 ' 86 teeth (N _r = 86), giving a ratio ρ of 0.395.

wobei τ_ODS das durch die Overdrive-Kupplung 66 übertragene Drehmoment ist, N₈₂ die Anzahl von Zähnen im Zahnradelement 82 ist und N₈₄ die Anzahl von Zähnen im Zahnradelement 84 ist. In einem Beispiel weist das Zahnradelement 84 83 Zähne auf (N₈₄ = 83), und das Zahnradelement 82 weist 59 Zähne auf (N₈₂ = 59). Die Beziehung in Gleichung (2) stellt eine Schätzung des durch die Overdrive-Kupplung 86 übertragenen Drehmoments basierend auf der Drehmomentabgabe durch die Kraftmaschine und dem Verhältnis des Generatordrehmoments zum Kraftmaschinendrehmoment (GRR) bereit, wobei das Übersetzungsverhältnis in den kämmenden Overdrive-Zahnradelementen 84 und 82 berücksichtigt wird.By using the GRR, torque values can be calculated and compared to estimate the torque in the overdrive clutch. For example

where τ _{ODS is} the one through the overdrive clutch 66 transmitted torque, N _{82 is} the number of teeth in the gear member 82 and N _{84 is} the number of teeth in the gear element 84 is. In one example, the gear member 84 83 teeth on (N ₈₄ = 83), and the gear element 82 has 59 teeth (N ₈₂ = 59). The relationship in equation (2) represents an estimate of that given by the overdrive clutch 86 transmitted torque based on the torque output by the engine and the ratio of the generator torque to the engine torque (GRR) ready, wherein the gear ratio in the meshing overdrive gear elements 84 and 82 is taken into account.

In addition, the torque through the ring gear 22 ' during synchronization of the overdrive clutch are represented as follows: τ _ring = - 1 / ρ + 1 (τ _eng ) (GRR) (3) where τ _ring through the ring gear 22 ' transmitted torque is. The torque through the ring gear 22 ' (τ _ring ) can be used in the main powertrain controls not described in detail in the present disclosure.

wobei τ_ODS→O das Overdrive-Kulungsdrehmoment an die Ausgangswelle 38' ist, wobei ein Übersetzungsverhältnis

berücksichtigt wird und N_34' und N₃₆' die Anzahl von Zähnen an den Zahnrädern 34' bzw. 36' sind, die Drehmoment von der Overdrive-Kupplung zur Ausgangswelle 38' übertragen. Natürlich kann eine beliebige Anzahl von Übersetzungsverhältnissen vorliegen, die die Drehzahl effektiv ändern, während Drehmoment dort hindurch übertragen wird. In einem Beispiel ist N_34' 23 und N_36' ist 59, was ein Übersetzungsverhältnis von 2,565 ergibt. Knowing the estimated torque (τ _ODS ) transmitted by the overdrive clutch allows the engine output to be reduced 16 ' and the engine 46 ' to control a smooth transition into or out of overdrive mode when the overdrive clutch switches between an engaged and a disengaged condition. The overdrive clutch torque to the wheels may be represented as follows, for example:

where τ _{ODS → O is} the overdrive constellation torque to the output shaft 38 ' is, being a gear ratio

is taken into account and N _{34 '} and N ₃₆ ' the number of teeth on the gears 34 ' respectively. 36 ' are the torque from the overdrive clutch to the output shaft 38 ' transfer. Of course, there may be any number of gear ratios that effectively change the speed while transmitting torque therethrough. In one example, N ₃₄ '23 and N _36' is 59, giving a gear ratio of 2.565.

wobei τ_out das durch die Ausgangswelle 38' übertragene Drehmoment ist, C_R→O die Übersetzungsverhältnisumwandlung von dem Hohlrad zum Ausgang ist (d. h. unter Berücksichtigung der Zahnräder 28', 30', 34' und 36') und τ_M→O das Motordrehmoment am Ausgang ist, wobei Übersetzungsverhältnisumwandlungen berücksichtigt werden (d. h. die Zahnräder 44', 32', 34' und 36' berücksichtigt werden). Es sei darauf hingewiesen, dass

auch als τ_ring→O ausgedrückt werden kann. Die Übersetzungsverhältnisumwandlung vom Hohlrad zum Ausgang C_R→O ergibt bei Multiplikation mit dem Kraftmaschinendrehmoment τ_eng das Kraftmaschinendrehmoment am Ausgang. Unter Verwendung der obigen Gleichung (5) kann die Drehmomentabgabe der Kraftmaschine 16' und des Motors 46' während des Einrückens oder Ausrückens der Overdrive-Kupplung 86 moduliert werden, um zu gewährleisten, dass die Gesamtdrehmomentabgabe τ_out einem angeforderten Drehmoment entspricht, während beim Einrücken oder Ausrücken der Overdrive-Kupplung 86 entstehende Schläge verhindert werden. Zum Beispiel kann die Abgabe des Motors 46' schneller moduliert werden als die der Kraftmaschine 16', und deshalb kann der Motor 46' dahingehend gesteuert werden, seine Drehmomentabgabe basierend auf dem Generatorreaktionsverhältnis GRR und anderen oben beschriebenen Beziehungen zu erhöhen oder zu verringern, wenn die Overdrive-Kupplung 86 eingerückt/ausgerückt wird. Andere Situationen, wie zum Beispiel während eines niedrigen Ladezustands der Batterie, können vorgeben, dass die Kraftmaschinenabgabe anstatt der Motorabgabe moduliert wird. Natürlich kann/können die Kraftmaschinenabgabe und/oder die Motorabgabe basierend auf den oben beschriebenen Beziehungen gesteuert werden.Using the variables and insights described above, this can be done through the output shaft 38 ' transmitting total torque can be represented as follows:

where τ _out through the output shaft 38 ' is transmitted torque, C _{R → O is} the gear ratio conversion from the ring gear to the output (ie, considering the gears 28 ' . 30 ' . 34 ' and 36 ' ) and τ _{M → O is} the engine torque at the output taking into account gear ratio conversions (ie, the gears 44 ' . 32 ' . 34 ' and 36 ' be taken into account). It should be noted that

can also be expressed as τ _{ring → O.} The gear ratio conversion from the ring gear to the output C _{R → O} multiplied by the engine torque τ _eng gives the engine torque at the output. Using the above equation (5), the torque output of the engine 16 ' and the engine 46 ' during engagement or disengagement of the overdrive clutch 86 be modulated to ensure that the total torque output τ _out corresponds to a requested torque, while engaging or disengaging the overdrive clutch 86 resulting blows are prevented. For example, the output of the engine 46 ' be modulated faster than the engine 16 ' , and therefore the engine can 46 ' be controlled to increase or decrease its torque output based on the generator reaction ratio GRR and other relationships described above when the overdrive clutch 86 indented / disengaged. Other situations, such as during a low state of charge of the battery, may dictate that the engine output be modulated rather than the engine output. Of course, the engine output and / or the engine output may be controlled based on the relationships described above.

9 FIG. 10 illustrates a drive train control algorithm according to the present disclosure in flowchart form. In particular, the flowchart in FIG 9 an example of a control strategy implemented by the controller to the engine and / or the engine based on one through the overdrive clutch 86 to control transferred estimated torque, as described in more detail above. at 200 the controller determines if the overdrive clutch is engaged or disengaged. This can be achieved in a variety of ways, such as by reading signal inputs from sensors in or around the clutch or determining a speed difference on opposite sides of the clutch

When the clutch is at least partially engaged, including times when the clutch is first driven to engage and "slips", at 202 the generator reaction ratio (GRR) according to equation (1) above. The GRR will be added 204 is filtered or at a rate limit to smooth the GRR over time, thereby preventing unwanted peaks in the torque measurements from interfering with the operation of the engine or engine controls. at 206 the GRR is then clipped with 0 and 1 to a minimum or maximum so that the GRR is not negative and does not exceed 1. That is after 206 resulting GRR is a value between 0 and 1 for use in overdrive clutch torque estimation.

at 208 the controller estimates the overdrive clutch torque using the clipped and filtered GRR according to equation (2). The estimated overdrive clutch torque may be at 210 be used in the calculation of the estimated overdrive clutch torque at the output according to equation (4). Thereafter, a torque control process may occur 212 be used by the controller for controlling the torque and power outputs of the engine and the engine to maintain the drivability of the vehicle, while requested torques and performances, in particular during times of entry into and exit from the overdrive mode, is met. For example, engine torque may be modulated by an amount based on the GRR and other variables above to further meet driver demands.

If at 200 If it is determined that the overdrive clutch is not engaged, the GRR will be included 214 set to 1. This effectively nullifies any generator reaction ratio in any of the above equations, thereby permitting operation of the engine, motor, and generator in the nominal mode of operation. Further, there is no torque transmitted through the opened clutch as in 216 and 218 displayed. It will be the main drive process 220 run in which the hybrid vehicle is controlled in a normal manner, that is not in overdrive.

On 10 Turning to, a control system becomes 300 of the generator 50 ' when operating in nominal operating mode. A target torque of the generator τ _{gen_des} when operating in nominal operating mode depends on the torque of the engine τ _{eng close} and can be represented as follows: τ _{gen_des} = - (τ _narrow × (ρ / ρ + 1)) (6) where τ _{gen_des} the desired torque of the generator 50 ' is, τ _eng the torque of the engine 16 ' is and (ρ / ρ + 1) the gear ratio between the engine 16 ' and the generator 50 ' is, wherein the engine with the carrier assembly 26 ' and the generator 50 ' with the sun wheel 24 ' connected is. The desired torque of the generator τ _{gen_des} is determined by block 302 and is placed in a summing node 304 _feed forward, where a generator _adjustment torque value τ _{gen_adj is} added to the desired torque of the generator τ _{gen_des} . The summation of the desired torque of the generator τ _{gen_des} and the generator _adjustment torque _value τ _{gen_adj} is then the generator 50 ' fed. The generator 50 ' then outputs an actual torque τ _{gen_act} and an actual speed ω _{gen_act} . The actual speed of the generator ω _{gen_act} is used as feedback in a summing node 306 where the actual speed of the generator ω _{gen_act is subtracted} from a set speed of the generator ω _{gen_des} , giving a generator speed _error ω _error . The generator speed _error ω _error becomes a forward clutch control 308 which generates the generator _{setting torque value} τ _{gen_adj} that is at the summing node 304 is added to the desired torque of the generator τ _{gen_des} . The forward clutch control 308 may include any combination of a proportional term, an integral term, and a derivative term, but is preferably a proportional-integral (PI) controller.

On 11A Turning to, a modified control system becomes 400 of the generator 50 ' shown. The modified tax system 400 includes operation of the generator 50 ' in nominal mode, in overdrive mode, and during transition between overdrive and nominal operating modes. The in the modified control system 400 used overdrive clutch 86 may be a rocker freewheel clutch and is represented as such. However, it will be appreciated that in addition to rocker one-way clutches, other types of overrunning clutches employing other types of engagement mechanisms may be used.

During operation of the generator 50 ' in nominal operating mode, the control system operates 400 under the same parameters as the control system 300 , In nominal mode is a first switching element 402 with a first switching node 404 connected and from a second switching node 406 separated. control block 408 controls the engagement and disengagement of the overdrive clutch 86 through the first switching element 402 , The first switching element 402 is through the first switching node 404 with the control block 410 connected. When the first switching element 402 with the control block 410 is connected, the control system operates either in nominal operating mode or returns by controlling the generator 50 ' to a base speed of the nominal operation mode back to the nominal operating mode. The desired torque of the generator τ _{gen_des} is determined by block 412 and is placed in a summing node 414 _feed forward, where a generator _adjustment torque value τ _{gen_adj is} added to the desired torque of the generator τ _{gen_des} . The summation of the desired torque of the generator τ _{gen_des} and the generator _adjustment torque _value τ _{gen_adj} is then the generator 50 ' by a second switching element 416 that with a first switching node 418 is connected and from a second switching node 420 is disconnected when the tax system 400 in the nominal operating mode. The second switching element 416 is with the control block 422 connected. The control block 422 Controls torque transfer to and from the overdrive clutch 86 , The generator 50 ' then outputs an actual torque τ _{gen_act} and an actual speed ω _{gen_act} . The actual speed of the generator ω _{gen_act} is considered to be a feedback to a summing node 424 where the actual speed of the generator ω _{gen_act is subtracted} from a set speed of the generator ω _{gen_des} , giving a generator speed _error ω _error . The generator speed _error ω _error becomes a forward clutch control 426 which generates the generator _{setting torque value} τ _{gen_adj} that is at the summing node 414 is added to the desired torque of the generator τ _{gen_des} . The forward clutch control 426 may include any combination of a proportional term, an integral term, and a derivative term, but is preferably a proportional-integral (PI) controller.

When transferring the generator 50 ' from the nominal operating mode to the overdrive operating mode becomes the first switching element 402 from the first switching node 404 disconnected and with the second switching node 406 connected. The first switching element 402 is then through the second switching node 406 with the control block 428 connected. The control block 428 controls the generator 50 ' to a desired freewheeling speed of the overdrive clutch 86 , After the actual speed of the generator ω _{gen_act} a desired freewheeling speed of the overdrive clutch 86 has reached and at collection block 430 is detected, the rocker arms of the overdrive clutch 86 at block 432 stretched out. After extending the rocker arms of the overdrive clutch, the speed of the generator 50 ' slowed down to a synchronous speed to the overdrive clutch 86 to engage. Upon engagement of the overdrive clutch, the second shift element becomes 416 from the first switching node 418 disconnected and with the second switching node 420 connected. The second switching element is then through the second switching node 420 with the control block 434 connected. Then the control block controls 434 the generator 50 ' for ramping out the torque from the planetary gear arrangement 20 ' and ramping to the overdrive clutch 86 , The actual torque of the generator τ _{gen_act} is in block 436 where the generator reaction ratio (GRR) is followed. The GRR can be followed during all operating times, including overdrive mode, nominal mode, and during transitions between overdrive and nominal modes.

When the generator 50 ' from the overdrive mode of operation to the nominal mode of operation, the second switching element becomes the second switching node 420 with the control block 434 connected. The control block 434 then controls the generator 50 ' for overrunning the torque of the overdrive clutch 86 and ramped to the planetary gear arrangement 20 ' , The actual torque of the generator τ _{gen_act} is again in block 436 where the generator reaction ratio (GRR) is followed. After ramping out of the torque from the overdrive clutch, the second switching element of the second switching node 420 separated and with the first switching node 418 connected. At by the second switching node 406 with the control block 428 connected first switching element 402 controls the control block 428 then the generator 50 ' to a desired freewheeling speed of the overdrive clutch 86 , If the actual speed of the generator ω _{gen_act} a desired freewheeling speed of the overdrive clutch 86 reached and at collection block 430 is detected, the rocker arms of the overdrive clutch 86 at block 432 withdrawn. After retracting the rocker arms of the overdrive clutch becomes the first switching element 402 from the second switching node 406 separated and through the first switching node 404 with the control block 410 connected. The control block 410 then controls the generator 50 ' to a base speed and returns to the nominal operating mode. A condition requiring a transition from the overdrive operating mode to the rated operating mode may be any of those described in U.S. Pat 4 found third operating conditions 106 be, but not limited to.

Further, in the transition from the overdrive mode to the rated operation mode, the torque for overrunning the one-way clutch increases 86 and ramped to the planetary gear arrangement 20 ' Required generator torque with increase in the value of the transmitted to the freewheel overdrive clutch torque τ _{OD_Clutch} . Furthermore, the torque of the generator 50 ' through the control block 434 be increased when the overdrive clutch 86 is disengaged by at control block 434 generating a torque _command equal to the torque τ _{OD_Clutch transferred to the overrunning} freewheel clutch. A torque command through control block 434 , which is equal to the torque τ _{OD_Clutch transferred to the overrunning} freewheel clutch a fast gain of torque that is close to the height of the torque to override the overdrive clutch 86 and ramped to the planetary gear arrangement 20 ' required torque should be. After the initial torque command, such as to transfer all torque from the overdrive clutch 86 and on the planetary gear arrangement 20 ' required, additional torque can be added resulting in zero or negligible torque on the overdrive clutch.

This when operating in overdrive mode or when transitioning between overdrive and nominal modes to the overrunning freewheel clutch 86 transmitted torque depends on the torque of the engine τ _eng and the generator reaction ratio (GRR) and can be represented as follows: τ _{OD_Clutch} = (1 - GRR) τ _narrow (7) where τ _{OD_Clutch is} the torque transmitted by the planetary gear _assembly 20 ' on the freewheel overdrive clutch 86 was transmitted, τ _eng the torque of the engine 16 ' and GRR is the generator reaction ratio.

Now on 11B Turning to, a control system becomes 500 the total torque output of the hybrid vehicle powertrain shown. The engine torque τ _eng is in block 502 entered, and the overdrive clutch torque on the output shaft 38 ' τ _{ODS → O} is called output from block 502 generated. The function in block 502 can be represented as follows:

The engine torque τ _eng is the input to the block 504 , and the ring gear torque at the output shaft 38 ' τ _{ring → O} is output as block 504 generated. The function in block 504 can be represented as follows: τ _ring = - (GRR) 1/1 + ρ (τ _eng ) × (C _{R → O} ) (9)

The target torque at the output shaft 38 ' τ is _{out_desired} in block 506 inputted, and then it becomes the motor torque at the output shaft 38 ' τ _{M → O} as output from block 506 generated. The function in block 506 can be represented as follows: τ _{M → O} = τ _{out_desired} - τ _{ring → O} - τ _{ODS → O} (10)

The overdrive clutch torque on the output shaft 38 ' τ _{ODS → O} , the ring gear torque at the output shaft 38 ' τ _{ring → O} and the motor torque at the output shaft 38 ' τ _{M → O} are then at summing nodes 508 sums up, leading to that through the output shaft 38 ' τ transferred _out total torque.

The terms used in the specification are terms of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments may be combined to form further embodiments of the invention, which may not be explicitly described or illustrated. While various embodiments may be presented as advantages or preferred over other embodiments or implementations of the prior art regarding one or more desired properties, as will be apparent to one of ordinary skill in the art, trade-offs may be made between one or more features or one or more features to achieve the desired overall system characteristics, depending on the particular application and implementation. These features may include, but are not limited to, cost, strength, longevity, life cycle cost, marketability, appearance, packaging, size, ease of maintenance, weight, manufacturability, ease of assembly, and so forth. Embodiments that are described as being less desirable than other embodiments or prior art implementations with respect to one or more features are thus not outside the scope of the disclosure and may be desirable for particular applications.

Claims (19)

Vehicle comprising: an engine and an electric machine connected to a planetary gear; a one-way clutch configured to transfer torque from the planetary gear to an overdrive wheel; and a controller programmed to increase a torque of the electric machine based on the torque transmitted from the planetary gear to the overdrive wheel in response to a condition requiring disengagement of the one-way clutch. The vehicle of claim 1, wherein the controller is further programmed to increase the torque of the electric machine until the torque transmitted to the overdrive wheel becomes zero. The vehicle of claim 2, wherein the controller is further programmed to set a speed of the electric machine so that the one-way clutch reaches a coasting state in response to the torque transmitted to the overdrive wheel becoming zero. The vehicle of claim 3, wherein the controller is further programmed to retract an override clutch engagement mechanism in response to the overrunning clutch reaching the overrunning condition. The vehicle of claim 4, wherein the controller is further programmed to exit an overdrive mode and to adjust the speed of the electric machine to enter a nominal operating mode in response to the retraction of the override clutch engagement mechanism. The vehicle of claim 4, wherein the one-way clutch is an electromagnetic toggle clutch, and wherein the controller is further programmed to retract the rocker arms of the electromagnetic toggle clutch in response to electronic deactivation of the electromagnetic toggle clutch. The vehicle of claim 1, wherein the condition is a reduction in power demand, an increase in power demand, braking, a reduction in vehicle speed, or an engine shutdown request. Hybrid vehicle, comprising: a planetary gear set having a sun gear, a carrier wheel and a ring gear, wherein the ring gear is configured to transmit torque to a drive wheel; an engine connected to the carrier wheel and configured to transmit torque to the planetary gear set; an overdrive wheel configured to transmit torque from the engine to the drive wheel; an overrunning clutch configured to transfer torque from the planetary gear set to the overdrive wheel when shifting between powertrain and overdrive modes of operation; a generator connected to the sun gear and configured to make the overrunning clutch free to rotate when rotated in a disengaging direction; and a controller programmed to, in response to a condition requiring switching from the powertrain overdrive mode to the powertrain rated operating mode, torque the generator in the disengaging direction according to a torque command applied to the overdrive from the planetary gear set Wheel transmitted torque is based to control. The vehicle of claim 8, wherein the controller is further programmed to change the torque of the generator until the torque transmitted to the overdrive wheel becomes zero. The vehicle of claim 9, wherein the controller is further programmed to adjust a speed of the generator in response to the torque transmitted to the overdrive wheel becoming zero, such that the one-way clutch reaches a coasting state. The vehicle of claim 10, wherein the controller is further programmed to retract an override clutch engagement mechanism in response to the overrunning clutch reaching the overrunning condition. The vehicle of claim 11, wherein the controller is further programmed to exit the powertrain overdrive mode in response to the retraction of the override clutch engagement mechanism and to adjust the speed of the generator to enter a powertrain rated operating mode. The vehicle of claim 11, wherein the one-way clutch is an electromagnetic toggle clutch, and wherein the controller is further programmed to retract the rocker arms of the electromagnetic toggle clutch in response to electronic deactivation of the electromagnetic toggle clutch. The vehicle of claim 8, wherein the condition is a reduction in power demand, an increase in power demand, braking, a reduction in vehicle speed, or an engine shutdown request. A method of controlling a vehicle having an engine and an electric machine connected to a planetary gear set and a one-way clutch configured to transfer torque from the planetary gear set to an overdrive wheel, the method comprising: in response to a condition requiring disengagement of the one-way clutch, increasing a torque of the electric machine based on the torque transmitted from the planetary gear set to the overdrive wheel. The method of claim 15, further comprising increasing the torque of the electric machine until the torque transmitted to the overdrive wheel becomes zero. The method of claim 16, further comprising, in response to the torque transmitted to the overdrive wheel becoming zero, adjusting a speed of the electric machine such that the one-way clutch reaches a coasting state. The method of claim 17, further comprising, in response to the overrunning clutch reaching the overrunning condition, retracting an override clutch engagement mechanism. The method of claim 18, further comprising, in response to the retraction of the override clutch engagement mechanism, exiting an overdrive mode and adjusting the speed of the electric machine to enter a nominal operating mode.

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